An investor wants to find the duration of$$ a$($n$)30-$year, $9\%$ semiannual$$ pay, noncallable bond$$ that's currently priced in the market at $$$$1,113\mathrm{.}12,$ to yield $8\%.$ Using a $200$ basis point change in$$ yield, find the effective duration of this bond $($Hint$$: use Equation$11\mathrm{.}11).$